Neve 10x1 Audience Reaction Mixer?

[Coop]

It's looking great! Great that you got it all back working.

 

[Ike Zimbel]

The only mistake I did was to reinstall the original 10K pots by wanting to keep everything as genuine as possible.

They are linear (as was the original output pot, which I find very strange), fragile and very unreliable. The push to mute functionnality, although pretty useful, has become very sensible and quite often keeps on getting stuck. They also feel terribly soft, I like hard to turn buttons.

I will for sure be replacing them for new A10Ks in the near future.

I'm pretty sure that I have 10 x 10kA Mod-Pots that I can sell you...probably with your choice of shaft size and type too. PM me for more info.

 

[Golgoth]

It's looking great! Great that you got it all back working.

Thanks a ton! I forgot to tell you it was done, you're a big part of the project's success!

 

[Coop]

Thanks a ton! I forgot to tell you it was done, you're a big part of the project's success!

You're welcome! Glad I could help a little

 

[ruffrecords]

Neve never used log pots except for P&G faders. All rotary pots were linear and were mostly slugged with half the pot value from wiper to ground. This gives close to 10dB attanuation at the mid point. The reason for this is that LIN pots are much repeatable and much less error prone than LOG pots.

Cheers

Ian

 

[Golgoth]

Neve never used log pots except for P&G faders. All rotary pots were linear and were mostly slugged with half the pot value from wiper to ground. This gives close to 10dB attanuation at the mid point. The reason for this is that LIN pots are much repeatable and much less error prone than LOG pots.

Cheers

Ian

That's very interesting. Would I need to re-install the resistors if I replace the current pots with logs or would it make no sense?

 

[ruffrecords]

That's very interesting. Would I need to re-install the resistors if I replace the current pots with logs or would it make no sense?

If you use logs you don't need the resistors.

Cheers

Ian

 

[Golgoth]

@ruffrecords One of the 10 original pots stopped working today. I was suspecting the "push to mute" mechanism so I tried bypassing it and using the pot's logs only. Audio is back, but when I turn that pot all the way down it kills all the other channels summed with that one.

Here is the original wiring using the "push to mute box". The 5k resistor is on the back on the two center pins.



To try and bypass the push-to-mute box, I tried soldering the red output wire to the blue wire going to the sommation. The other blue and green are grounds going into a pigtail. I added the 5k resistor at the cables junctions where they are soldered together.



What am I missing?

Thanks!

 

[ruffrecords]

The switch wiring looks odd the me. For those push-buttons the wiper is usually the middle pin. In the top picture the middle pin of the top row is not connected so that section does nothing even though the other two pins are connected to something. The opposite is true of the bottom row.

Cheers

Ian

 

[Golgoth]

Hi Ian,

I simply copied the original Neve wiring of another Audience Reaction Mixer:



It works very well on the other working pots/switches to mute the channel when pushed. I've tried testing continuity between all these pins but they do not make sense to me either tho so it is hard to understand what is going on.

 

[ruffrecords]

Yes, it has me scratching my head too.

Cheers

Ian

 

[Golgoth]

Any idea about why this one pot is killing the gain of all the other ones summed with it when turned all the way down? I thought I could simply bypass the push-to-mute box like I did but something seems wrong even tho the wiring is functionnal.

 

[ruffrecords]

Check the bus feed resistor from the faulty one.

Cheers

Ian

 

[Golgoth]

@ruffrecords I managed to solve the issue by reconnecting the wires to the push-to-mute unit. While measuring for continuity between both sides I found that one connexion was dead when comparing to all the other working pots. I simply moved the corresponding resistor's leg to another pin that also have a connexion to the pin I wanted on the other side! Working like a charm now!

 

[Golgoth]

Looking great in the racks thanks to @fffaustino 's original blue knob for the output gain!

 

[Ike Zimbel]

Hi Ian,

I simply copied the original Neve wiring of another Audience Reaction Mixer:

View attachment 90292

It works very well on the other working pots/switches to mute the channel when pushed. I've tried testing continuity between all these pins but they do not make sense to me either tho so it is hard to understand what is going on.

I think what I'm seeing here is: When switch is Out (no Mute) the wiper is routed through the resistor on the back of the switch to the blue (presumably signal) wire on the other side. When the switch is In (Mute) the resistor is shorted to ground (green wire). So, with the pot turned full CCW, it is still going through that resistor (a summing R?) which is why it doesn't ground out the rest of the bus.

 

[Golgoth]

When switch is Out (no Mute) the wiper is routed through the resistor on the back of the switch to the blue (presumably signal) wire on the other side.

That's what I figured when checking continuity. I previously thought the resistor had to always be between the wiper and ground (as Ian mentionned a few posts ago: "All rotary pots were linear and were mostly slugged with half the pot value from wiper to ground."). But that was the bus feed resistor itself!

 

[fffaustino]

Looking great in the racks thanks to @fffaustino 's original blue knob for the output gain!

View attachment 90322

Looks great, congrats!!!

 

[fixation]

I've got a 6 Channel in 1 out that I'd like to change up to 2 out. Will be following this thread and picking your brain.

 

[aurt]

It turns out that A3559 was one of three 32 channel TV consoles made for CBS in 1975. Apparently CBS sere still using a 150 ohm termination to define 0dBm so all the outputs had to be capable of doing this. It was this that spurred the change to using dBu instead of dBm at Neve. Here is a little video from Rupert.



Cheers

Ian

IIRC, the dBm is a holdover from the telegraph. Power transmission is important in long distance wired communication. Matching input, output, and line impedances results in only dropping 3 dB, rather than more if they are not matched. I've heard tell that the origin of the 600 Ohm standard was that it's the characteristic impedance of two 12 ga. wires strung 12" apart, which was the original telegraph spec. Telephony assimilated the amplifiers and standards from the telegraphs, and audio recording swiped from that. What CBS was doing at 150 is beyond me.

Neve was apparently an early adopter of the realization that a studio isn't concerned with power transfer, and rightly so. Later, the industry followed suit, ditching the 600 Ohm standard for the 10k input/50 Ohm output bridging standard currently in favor. All the better to mult you with, my dear. Fun to hear where dBu came from.